package com.nowcoder.topic.list.simple;

/**
 * NC33 合并两个排序的链表
 * @author d3y1
 */
public class NC33 {
    /**
     * 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可
     *
     * 递归
     *
     * @param pHead1 ListNode类
     * @param pHead2 ListNode类
     * @return ListNode类
     */
    public ListNode Merge (ListNode pHead1, ListNode pHead2) {
        if(pHead1 == null){
            return pHead2;
        }
        if(pHead2 == null){
            return pHead1;
        }

        if(pHead1.val < pHead2.val){
            pHead1.next = Merge(pHead1.next, pHead2);
            return pHead1;
        }else{
            pHead2.next = Merge(pHead1, pHead2.next);
            return pHead2;
        }
    }

    private class ListNode {
        int val;
        ListNode next = null;
        public ListNode(int val) {
            this.val = val;
        }
    }
}